Pakistan stepped up security Monday around its nuclear facilities, military bases and government offices after a raid by 10 heavily armed Tehreek-e-Taliban Pakistan attackers brought chaos to Karachi international airport and killed 18 security guards. TTP commanders said the attack was revenge for the death of its former leader Hakimullah Mehsud in a drone strike last year. He said attacks would continue “as long as we are breathing.” Mohyuddin Wani, the Pakistani prime minister's press secretary, said the attack was designed to shut down the country's entire aviation industry. "Their intention was an all-out spectacular attack, eliminating 20 aircraft and killing more than 200 passengers," he said.